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The entire history of the world as told to us by the dirty, filthy rocks 4.6 bya Precambrian Time Phanerozoic Eon (the 3 Eras) 544 mya Present •4.6 bya -- begins when Earth forms from gas and dust (we think) •4 bya – oceans form •2.5 bya – organisms begin photosynthesis, makes more oxygen in the atmosphere. •Most organisms were bacteria, algae, or soft-bodied animals Paleozoic Era Explosion of life 245 mya Mesozoic Era 66.4 Cenozoic mya Era Age of the dinosaurs Rise of the mammals Present 544 mya •Shallow seas cover much of the land •Explosion of life in seas •Invertebrates with shells appear Cambrian 544 mya Ordovician 505 mya •Ice cap covers North America •Early vertebrates – jawless fish – become common •Coral reefs develop •Land plants appear •Insects & spiders appear Silurian 438 mya •Winged insects •First true reptiles •N. America & Europe are covered in swamps Devonian Carboniferous Permian 408 mya •Age of fishes begins •First amphibians •Forests grow in swampy areas 360 mya 286 mya •Pangaea forms •Reptiles become dominant •Mass extinction kills many marine invertebrates 245 mya Triassic 245 mya Jurassic 208 mya •Age of Reptiles begins •First dinosaurs appear •First mammals appear •Turtles & crocodiles appear Cretaceous 144 mya •Pangaea continues to break apart •Sea levels rise •Largest dinosaurs thrive •First birds appears •First flying reptiles appear (pterosaurs) 66.4 mya •Widespread volcanic activity •First flowering plants appear •Tyrannosaurus Rex •Mass extinction kills dinosaurs 66.4 mya •Age of mammals begins •Whales and dolphins appear •Horses, elephants, bears, rodents, and primates appear •Continents move into present locations. 1.6 mya •Thick glaciers advance in most of N. America & Europe, all of Antarctica, and parts of S. American and Asia. •Giant mammals in N. America & Eurasia •Mr. Cruz is born – the people rejoice! Present Tertiary